MERCEDES-BENZ CLS 2018 Repair Manual

secured properly. The special seat belt retrac-
tor is disabled and the inertia real draws in a
portion of the seat belt. The seat belt cannot
be immediately refastened. There is an
increased risk of injury, possibly even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. Reactivate
the special seat belt retractor and secure the
child restraint system properly.
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor.
When activated, the special seat belt retractor
ensures that the seat belt will not slacken once
the child restraint system has been secured.
Installing a child restraint system: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Pull the seat belt smoothly from the belt out-
let. X
Engage the seat belt tongue in the belt buckle.
Activating the special seat belt retractor: X
Pull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat belt
retractor is activated. X
Push the child seat restraint system down so
that the seat belt is tight and does not loosen.
Removing a child restraint system and deacti-
vating the special seat belt retractor: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Press the release button of the belt buckle,
hold the belt tongue firmly and guide it back
towards the belt outlet.
The special seat belt retractor is deactivated.
Child restraint system
The use of seat belts and child restraint systems
is required by law in: R
all 50 states R
the U.S. territories R
the District of Columbia R
all Canadian provinces You can obtain further information about the
correct child restraint system from any author-
ized Mercedes-Benz Center.
G WARNING
If the child restraint system is installed incor-
rectly on a suitable seat, it cannot protect as
intended. The child cannot then be restrained
in the event of an accident, heavy braking or
sudden changes of direction. There is an
increased risk of injury, possibly even fatal.
Make sure that you observe the child restraint
system manufacturer's installation instruc-
tions and the notes on use. Please ensure,
that the base of the child restraint system is
always resting completely on the seat cush-
ion. Never place objects, e.g. cushions, under
or behind the child restraint system. Only use
child restraint systems with the original cover
designed for them. Only replace damaged
covers with genuine covers.
G WARNING
If the child restraint system is installed incor-
rectly or is not secured, it can come loose in
the event of an accident, heavy braking or a
sudden change in direction. The child
restraint system could be thrown about, strik-
ing vehicle occupants. There is an increased
risk of injury, possibly even fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions.
You will find further information on stowing
objects, luggage or loads under "Loading guide-
lines" ( Y
page 242).
G WARNING
Child restraint systems or their securing sys-
tems which have been damaged or subjected
to a load in an accident can no longer protect
as intended. The child cannot then be
restrained in the event of an accident, heavy
braking or sudden changes of direction. There
is an increased risk of injury, possibly even
fatal.Children in the vehicle 59
Safety Z

Replac e child restrain t systems whic h hav e
been damaged or subjecte d to a load in an
acciden t as soo n as possible. Hav e th e secur-
ing systems on th e child restrain t system
checke d at a qualified specialist workshop,
before you instal l a child restrain t system
again .
The securin g systems of child restrain t systems
are: R
th e seat belt systemR
th e LATCH-type (ISOFIX) securin g ringsR
th e Top Tether anchorages
If it is absolutely necessar y to carry a child on
th e front-passenger seat , be sur e to observ e th e
information on th e "Occupant Classification
Syste m (OCS)" ( Y
page 49). There you will also
fin d information on deactivating th e front-
passenger fron t air bag.
All child restrain t systems mus t mee t th e fol -
lowin g standards :R
U.S. Federal Motor Vehicl e Safet y Standards
21 3 and 22 5R
Canadian Motor Vehicl e Safet y Standards
21 3 and 210. 2
Confirmation that th e child restrain t system cor-
responds to th e standards can be foun d on an
instruction label on th e child restrain t system.
This confirmation can also be foun d in th e instal -
lation instruction s that are included wit h th e
child restrain t system.
Observ e th e warning labels in th e vehicl e inte-
rio r and on th e ch ild re strain t s
ystem.
LATCH-type (ISOFIX) child seat secur-
ing system
G WARNIN G
LATCH-type (ISOFIX) child restrain t systems
do no t offer sufficien t protective effec t for
children whos e weigh t is greate r than 48 lbs
(22 kg ) who are secured usin g th e safet y belt
integrate d in th e child restrain t system. In th e
event of an accident, a child might no t be
restrained correctly. This poses an increased
ris k of injury or eve n fatal injury.
If th e child weigh s mor e than 48 lbs (22 kg),
only use LATCH-type (ISOFIX) child restrain t systems wit h whic h th e child is also secured
wit h th e vehicl e seat belt . Als o secure th e
child restrain t system wit h th e Top Tether
belt , if available.
Always comply wit h th e manufacturer' s instal -
lation and operating instruction s for th e child
restrain t system used .
Before every trip, mak e sur e that th e LATCH -
typ e (ISOFIX) child restrain t system is engage d
correctl y in bot h LATCH-type (ISOFIX) securin g
rings
When installin g th e LATCH-type (ISOFIX) child
restrain t system, fol d protective cap s D of
securin g rings C inwards .X
Install th e LATCH-type (ISOFIX) child restrain t
system on bot h LATCH-type (ISOFIX) securin g
rings C .
ISOFIX is a standardize d securin g system for
specially designed child restrain t systems on
th e rear seats. LATCH-type (ISOFIX) securin g
rings for two LATCH-type (ISOFIX) child restrain t
systems are installed on th e lef t and right of th e
rear seats.
Non-LATCH-typ e (ISOFIX) child seat s may also
be used and can be installed usin g th e vehicle's
seat belt system. Install th e child seat according
to th e manufacturer' s instructions.
Top Tether
Introduction
Top Tether provide s an additional connection
between th e child restrain t system secured wit h
a LATCH-type (ISOFIX) system and th e vehicle.
This help s reduce th e ris k of injury eve n further.
If th e child restrain t system is equipped wit h a
Top Tether belt , this should always be used .60
Children in the vehicle
Safety

Important safety notes
G WARNIN G
If th e rear seat backrest s are no t locked, they
could fol d forwards in th e event of an acci-
dent, heav y braking or sudde n changes of
direction . As a result , child restrain t systems
canno t perfor m their intended protective
function . Rear seat backrest s that are no t
locke d can also caus e additional injuries, e.g.
in th e event of an accident. This poses an
increased ris k of injury or eve n fatal injury.
Always loc k rear seat backrest s after instal -
lin g a Top Tether belt . Observ e th e loc k veri-
fication indicator. Adjus t th e rear seat backr -
est s so that they are in an upright position .
If th e rear seat backrest is no t engage d and
locked, this will be shown in th e multifunction
display in th e instrumen t cluster. A warning tone
also sounds.
Top Tether anchorages
Top Tether anchorage points

You can thus avoid the risks that could arise as
a result of: R
an incorrectly categorized person in the front-
passenger seat R
the unintentional deactivation of the front-
passenger front air bag R
the unsuitable positioning of the child
restraint system, e.g. too close to the dash-
board
Rearward-facing child restraint system If it is absolutely necessary to install a rearward-
facing child restraint system on the front-
passenger seat, always make sure that the
front-passenger front air bag is deactivated.
Only if the PASSENGER AIR BAG OFF indicator
lamp is permanently lit ( Y
page 42) is the front-
passenger front air bag deactivated.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Forward-facing child restraint system If it is absolutely necessary to install a forward-
facing child restraint system on the front-
passenger seat, always move the front-
passenger seat as far back as possible. The
entire base of the child restraint system must
always rest on the seat cushion of the front-
passenger seat. The backrest of the child
restraint system must lie as flat as possible
against the backrest of the front-passenger
seat. The child restraint system must not touch
the roof or be subjected to a load by the head
restraint. Adjust the angle of the seat backrest
and the head restraint position accordingly.
Always make sure that the shoulder belt strap is
correctly routed from the vehicle belt outlet to
the shoulder belt guide on the child restraint
system. The shoulder belt strap must be routed
forwards and downwards from the vehicle belt
outlet. If necessary, adjust the vehicle belt out-
let and the front-passenger seat accordingly.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions. Child-proof locks
Important safety notes
G WARNING
If children are traveling in the vehicle, they
could: R
open doors, thus endangering other people
or road users R
exit the vehicle and be caught by oncoming
traffic R
operate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the
vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle.
Override feature for: R
the rear doors ( Y
page 63)R
the rear side windows ( Y
page 63)
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P .R
start the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
G WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.62
Children in the vehicle
Safety

G WARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro-
tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
Child-proof locks for the rear doors
You secure each door individually with the child-
proof locks on the rear doors. A door secured
with a child-proof lock cannot be opened from
inside the vehicle. When the vehicle is unlocked,
the door can be opened from the outside. X
To activate: press the child-proof lock lever
up in the direction of arrow C .X
Make sure that the child-proof locks are work-
ing properly. X
To deactivate: press the child-proof lock
lever down in the direction of arrow D . Override feature for the rear side win-
dows X
To activate/deactivate: press button D .
If indicator lamp C is lit, operation of the rear
side windows is disabled. Operation is only
possible using the switches in the driver's
door. If indicator lamp C is off, operation is
possible using the switches in the rear com-
partment.
Pets in the vehicle
G WARNING
If you leave animals unattended or unsecured
in the vehicle, they could press buttons or
switches, for example.
As a result, they could: R
activate vehicle equipment and become
trapped, for example R
activate or deactivate systems, thereby
endangering other road users
Unsecured animals could also be flung around
the vehicle in the event of an accident or sud-
den steering or braking, thereby injuring vehi-
cle occupants. There is a risk of an accident
and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals properly during
the journey, e.g. use a suitable animal trans-
port box.Pets in the vehicle 63
Safety Z

Drivin g safet y systems
Overview of drivin g safet y systemsIn this section , you will fin d information about
th e followin g drivin g safet y systems :R
AB S ( A n ti-loc k B rakin g S ystem)
( Y
page 64)R
BA S ( B rak e A ssist S ystem) ( Y
page 65)R
BA S PLU S ( B rake A s sis t S ystem PLUS) wit h
Cross-Traffic Assis t ( Y
page 65)R
COLLISION PREVENTION ASSIST PLU S
( Y
page 67 )R
ES P ®
( E lectronic S t ability P r ogram)
( Y
page 69)R
EB D ( E lectroni c B rak e forc e D istribution )
( Y
page 72 )R
ADAPTIV E BRAKE ( Y
page 72 )R
PRE-SAF E ®
Brak e ( Y
page 72 )
Important safet y notesIf you fail to adapt your drivin g style or if you are
inattentive , th e drivin g safet y systems can nei-
ther reduce th e ris k of an acciden t no r override
th e laws of physics. Driving safet y systems are
merely aids designed to assist driving. You are
responsible fo r maintainin g th e distanc e to th e
vehicle in front, fo r vehicle speed, fo r braking in
goo d time, and fo r stayin g in lane. Always adapt
your drivin g style to suit th e prevailin g road and
weather condition s and maintain a saf e distanc e
from th e vehicle in front. Drive carefully.
The drivin g safet y systems described only wor k
as effectively as possible when there is ade-
quat e contact between th e tires and th e road
surface. Pay particular attention to th e informa-
tion regardin g tires , recommended minimum
tire tread depths etc. in th e "Wheels and tires "
section ( Y
page 292).
In wintr y drivin g conditions, always use winte r
tires (M+ S tires )a nd if necessary, snow chains.
Only in this way will the driving safety systems
described in this section work as effectively as
possible. ABS (Anti-lock Braking System)
General information ABS regulates brake pressure in such a way that
the wheels do not lock when you brake. This
allows you to continue steering the vehicle when
braking.
The % ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
ABS works from a speed of about 5 mph
(8 km/h), regardless of road-surface conditions.
ABS works on slippery surfaces, even when you
only brake gently.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 64).
G WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid-
ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp ( Y
page 229) and dis-
play messages which may be shown in the
instrument cluster ( Y
page 204).
Braking X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking sit-
uation is over. X
To make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions, and functions as a
reminder to take extra care while driving.64
Driving safety systems
Safety

BAS (Brake Assist System)
General information BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 64).
G WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
BAS PLUS (Brake Assist PLUS) with
Cross-Traffic Assist
General information BAS PLUS can help you to minimize the risk of a
collision with a vehicle or a pedestrian and
reduce the effects of such a collision. If BAS
PLUS detects a danger of collision, you are
assisted when braking.
i Pay attention to the important safety notes
in the "Driving safety systems" section
( Y
page 64).
BAS PLUS is only available on vehicles with the
Driving Assistance package.
For BAS PLUS to assist you when driving, the
radar sensor system and the camera system
must be operational. With the help of a sensor system and a camera
system, BAS PLUS can detect obstacles: R
that are in the path of your vehicle for an
extended period of time R
that cross the path of your vehicle
In addition, pedestrians in the path of your vehi-
cle can be detected.
BAS PLUS detects pedestrians by using typical
characteristics such as the body contours and
posture of a person standing upright.
If the radar sensor system or the camera system
is malfunctioning, BAS PLUS functions are
restricted or no longer available. The brake sys-
tem is still available with complete brake boost-
ing effect and BAS.
i Observe the restrictions described in the
"Important safety notes" section
( Y
page 65).
Important safety notes
G WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations.
In such cases, BAS PLUS may: R
intervene unnecessarily R
not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
G WARNING
BAS PLUS cannot always clearly identify peo-
ple, this is especially the case if they are mov-
ing. BAS PLUS cannot intervene in these
cases. There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
G WARNING
BAS PLUS does not react: R
to small people, e.g. children R
to animals R
to oncoming vehicles R
when corneringDriving safety systems 65
Safety Z

As a result, BAS PLUS may not intervene in all
critical situations. There is a risk of an acci-
dent.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
In the event of snowfall or heavy rain, the rec-
ognition can be impaired.
Recognition by the radar sensor system is also
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle is traveling in front, e.g. a
motorbike R
a vehicle is traveling in front on a different line R
vehicles quickly move into the radar sensor
system detection range
Recognition by the camera system is also
impaired in the event of: R
dirt on the camera or if the camera is covered R
glare on the camera system, e.g. from the sun
being low in the sky R
darkness R
or if: -
pedestrians move quickly, e.g. into the path
of the vehicle -
the camera system no longer recognizes a
pedestrian as a person due to special cloth-
ing or other objects -
a pedestrian is concealed by other objects -
the typical outline of a person is not distin-
guishable from the background
Following damage to the fro nt end of the vehicle,
h
ave the configuration and operation of the
radar sensors checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
Following damage to the windshield, have the
configuration and operation of the camera sys-
tem checked at a qualified specialist workshop. Function To avoid a collision, BAS PLUS calculates the
brake force necessary if: R
you approach an obstacle, and R
BAS PLUS has detected a risk of collision
At speeds of under 20 mph (30 km/h) : if you
depress the brake pedal, BAS PLUS is activated.
The increase in brake pressure will be carried
out at the last possible moment.
At speeds of above 20 mph (30 km/h) : if you
depress the brake pedal sharply, BAS PLUS
automatically increases the brake pressure to a
degree suited to the traffic situation.
BAS PLUS provides braking assistance in haz-
ardous situations with vehicles in front within a
speed range between 4 mph (7 km/h) and
155 mph (250 km/h).
Up to a speed of approximately 44 mph
(70 km/h), BAS PLUS may react to: R
stationary objects in the path of your vehicle,
e.g. stopped or parked vehicles R
pedestrians in the path of your vehicle R
obstacles crossing your path, which move in
the detection range of the sensors and are
recognized by them
i If BAS PLUS demands particularly high brak-
ing force, preventative passenger protection
measures (PRE-SAFE ®
) are activated simulta-
neously. X
Keep the brake pedal depressed until the
emergency braking situation i s over.
ABS prevents the wheels from locking.
BAS PLUS is deactivated and the brakes func-
tion as usual, if: R
you release the brake pedal. R
there is no longer a risk of collision. R
no obstacle is detected in front of your vehi-
cle. R
you depress the accelerator pedal. R
you activate kickdown.66
Driving safety systems
Safety

COLLISION PREVENTION ASSIST
PLUS
General information
i Observe the "Important safety notes" sec-
tion ( Y
page 64).
COLLISION PREVENTION ASSIST PLUS consists
of a distance warning function with an autono-
mous braking function and adaptive Brake
Assist.
COLLISION PREVENTION ASSIST PLUS can help
you to minimize the risk of a front-end collision
with a vehicle ahead or reduce the effects of
such a collision.
If COLLISION PREVENTION ASSIST PLUS
detects that there is a risk of a collision, you will
be warned visually and acoustically. If you do not
react to the visual and audible collision warning,
autonomous braking can be initiated in critical
situations. If you apply the brake yourself in a
critical situation, the COLLISION PREVENTION
ASSIST PLUS adaptive Brake Assist assists you.
Important safety notes In particular, the detection of obstacles can be
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is snow or heavy rain R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle is traveling in front, e.g. a
motorbike R
a vehicle is traveling in front on a different line R
new vehicles or after a service on the COLLI-
SION PREVENTION ASSIST PLUS system
Observe the notes in the section on breaking-
in ( Y
page 122).
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle. Activating/deactivating The COLLISION PREVENTION ASSIST PLUS is
automatically active after switching on the igni-
tion.
You can activate or deactivate COLLISION PRE-
VENTION ASSIST PLUS in the on-board com-
puter ( Y
page 196). When deactivated, the dis-
tance warning function and the autonomous
braking function are also deactivated.
If COLLISION PREVENTION ASSIST PLUS is
deactivated, the

There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and do not rely solely on the distance
warning function.
Function At and above a speed of approximately 4 mph
(7 km/h), the distance warning function warns
you if you rapidly approach a vehicle in front. An
intermittent warning tone will then sound, and
the